Luyang Liu,Xuanyue Yu,Yuting Huang,Cuiting Liu,Xinyi Xie,Zhongzhen Wu,Jintian Lin,Benshui Shu
Diaphorina citri is a serious citrus pest. Dinotefuran is highly insecticidal against D. citri. To analyze the sublethal effects of dinotefuran on D. citri adults, an indoor toxicity test was performed, which revealed that the lethal concentration 50 (LC50) values were 4.23 and 0.50 μg/mL for 24 and 48 h treatments, respectively. RNA-Seq led to the identification of 71 and 231 differentially expressed genes (DEGs) after dinotefuran treatments with LC20 and LC50 doses, respectively. Many of the DEGs are significantly enriched in the apoptosis pathway. Dinotefuran-induced apoptosis in the gut cells was confirmed through independent assays of 4′,6-diamidino-2-phenylindole (DAPI) and TdT-mediated dUTP nick end labeling (TUNEL) staining. Increased levels of reactive oxygen species (ROS) and a loss of mitochondrial membrane potential were observed. Four caspase genes were identified, and dinotefuran treatments resulted in increased mRNA levels of DcCasp1 and DcCasp3a. These findings shed light on the sublethal effects of dinotefuran on D. citri.
Ammonium sulfate and dinotefuran are widely used in agricultural practices; however, limited knowledge exists regarding the potential risks associated with their co-exposure. In this study, the impact of ammonium sulfate on the degradation of dinotefuran in four soils was investigated, and the formation of the main metabolites UF, DN, MNG, and NG was also determined. The underlying mechanisms were explored by the impact of ammonium sulfate on soil physicochemical properties as well as soil microorganisms. The half-life of dinotefuran sole exposure in soils were determined between 27.47 and 60.05 days. Co-exposure of ammonium sulfate significantly impeded the degradation of dinotefuran, resulting in 1.70–5.05 times longer half-life, reduced the content of the metabolites and changed their composition. Ammonium sulfate induced significant alterations in the structure and dominance of bacterial communities in the soils. The reduced relative abundance of Bacteroidota , Proteobacteria and Chloroflexi phyla related to dinotefuran degradation. Ammonium sulfate also led to a decrease in soil pH and organic matter content, which were negatively correlated with the degradation. PLS-SEM analysis revealed soil microbial diversity had a significant impact on the degradation of dinotefuran. The findings serve as a cautionary note regarding the risks of co-exposure to fertilizers and pesticides.